This invention relates generally to a laser goniometer which allows the user to sight along a geologic feature and orient a laser to match the attitude of the feature directly. Accurate, dependable measurement of bearings and directions are required for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. Subterranean sites presently being investigated are in rock with natural magnetism and also contain steel structures.
Previously, mapping of shafts could be done with extensive survey support to give geologists reference angles from which to measure the angles of the geologic features. This process was tedious and quite slow, resulting in high costs. Under these conditions, a surveyed reference (strike rail), is necessary with all directions or bearings related to the reference. Utilizing a conventional strike rail is time consuming and therefore extremely expensive. Previous methods consisted of obtaining bearings or directions from surveyed rails that had to be pre-positioned around the periphery of the work platform. This method is not compatible with a shaft sinking galloway. Magnetic compasses have been used but are not dependable.
The laser goniometer is not dependent on magnetic fields for determining the strike and dip of geologic features, as are more conventional geologic instruments such as the Brunton Compass. The laser goniometer relies on a surveyed reference rail and geometric means for obtaining strikes and dips, much as a surveying transit relies on reference points for determining angles of traverse. Formerly this would involve measuring the strike (orientation of the intersection of a geologic feature with a horizontal plane) by the use of a surveying transit and some type of protractor, and then using a Brunton Compass to measure the dip (angle from horizontal). The instant invention overcomes the deficiencies of the prior art by the use of a single instrument incorporating a collimated laser beam with a direct-reading base which can be indexed to a know reference specifically designed for use in measuring.